根据时间获取单号

public static String getCode(){
        String uuId="";
        Calendar now = Calendar.getInstance();
        System.out.println("年: " + now.get(Calendar.YEAR));
        System.out.println("月: " + (now.get(Calendar.MONTH) + 1) + "");
        System.out.println("日: " + now.get(Calendar.DAY_OF_MONTH));
        System.out.println("时: " + now.get(Calendar.HOUR_OF_DAY));
        System.out.println("分: " + now.get(Calendar.MINUTE));
        System.out.println("秒: " + now.get(Calendar.SECOND));
        System.out.println("当前时间毫秒数：" + now.getTimeInMillis());
        System.out.println(now.getTime());
        uuId=String.valueOf(now.get(Calendar.YEAR))+String.valueOf(((now.get(Calendar.MONTH) + 1)))
        +String.valueOf(now.get(Calendar.DAY_OF_MONTH))+String.valueOf(now.get(Calendar.HOUR_OF_DAY))
        +String.valueOf(now.get(Calendar.MINUTE))+String.valueOf(now.get(Calendar.SECOND))
        +String.valueOf(getRandom(6));
        String current_time=getFomartDate("yyyyMMddHHmmss");
        uuId=current_time+String.valueOf(getRandom(6));
        return uuId;
    }
    /**
     * 生成固定长度随机码
     * @param n 长度
     */
    private static long getRandom(long n) {
        long min = 1, max = 9;
        for (int i = 1; i < n; i++) {
            min *= 10;
            max *= 10;
        }
        long rangeLong = (((long) (new Random().nextDouble() * (max - min)))) + min;
        return rangeLong;
    }
    public static String getFomartDate(String format){
        return new SimpleDateFormat(format).format(new Date());
    }
    public static void main(String[] args) throws ParseException {
        String uuId="";
        Calendar now = Calendar.getInstance();
        System.out.println("年: " + now.get(Calendar.YEAR));
        System.out.println("月: " + (now.get(Calendar.MONTH) + 1) + "");
        System.out.println("日: " + now.get(Calendar.DAY_OF_MONTH));
        System.out.println("时: " + now.get(Calendar.HOUR_OF_DAY));
        System.out.println("分: " + now.get(Calendar.MINUTE));
        System.out.println("秒: " + now.get(Calendar.SECOND));
        System.out.println("当前时间毫秒数：" + now.getTimeInMillis());
        System.out.println(now.getTime());
        uuId=String.valueOf(now.get(Calendar.YEAR))+String.valueOf(((now.get(Calendar.MONTH) + 1)))
        +String.valueOf(now.get(Calendar.DAY_OF_MONTH))+String.valueOf(now.get(Calendar.HOUR_OF_DAY))
        +String.valueOf(now.get(Calendar.MINUTE))+String.valueOf(now.get(Calendar.SECOND))
                +String.valueOf(getRandom(6));
        String current_time=getFomartDate("yyyyMMddHHmmss");
        uuId=current_time+String.valueOf(getRandom(6));
        System.out.println("字符串转成日期：" + uuId);
    }